Perseids Meteor Information Source Wikipedia
The Perseids (pronounced /ˈpɜrsiː.ɨdz/ us dict: pûr′·sē·ĭdz) are a prolific meteor shower associated with the comet Swift-Tuttle. The Perseids got its name because of its point of origin, which is called the radiant that lies in the constellation Perseus. Meteor showers occur when Earth moves through a meteor stream. The stream in this case is called the Perseid cloud and it stretches along the orbit of the Comet Swift-Tuttle.
The Perseid meteor shower has been observed for about 2000 years, with the first known information on this meteor shower coming from the Far East. In early medieval Europe, the Perseids came to be known as the "tears of St. Lawrence."
The shower is visible from mid-July each year, with the greatest activity between August 8 and 14, peaking about August 12. During the peak, the rate of meteors reaches 60 or more per hour. They can be seen all across the sky, but because of the path of Swift-Tuttle's orbit, Perseids are primarily visible in the northern hemisphere. This year (2009) the Peak hourly zenith rate will be about 120, but fainter meteors will be washed out by a waning gibbous moon.